问题
I'm using roxygen2 for my package description and I want to have mathematic equations in my documentation. For example I want to write n_{u} like a formula. When I write \eqn{n_{u}} in @details nothing happens but the text is italic. I document the package with control, shift and d and then i push "Clean and rebuild". Did I forget anything?
回答1:
This is expected behaviour. The R documentation format doesn't have "real" equations like you might get from Mathjax or another fully-fledged Latex engine; it uses a basic representation that just copies your equation text but sets it in italics. Think of it as more akin to code, rather than mathematical notation.
回答2:
\eqn{n_u} is for the PDF documentation.
Write that instead:
\ifelse{html}{\out{n<sub>u</sub>}{\eqn{n_u}}
The syntax is:
\ifelse{html}{\out{HTML CODE}}{\eqn{LATEX-LIKE CODE}{ASCII}}
with {ASCII} optional is for the text documentation. HTML CODE is for the HTML documentation, and LATEX-LIKE CODE is for the PDF documentation.
来源：https://stackoverflow.com/questions/54998615/equations-in-r-package-documentation-do-not-work